On Tue, 30 Dec 2003 06:21:37 UTC,
) wrote:


"Excess"(?) Iron has not caused algae in any tank I have critically
tested it on.
Algae needs such a small amount and so do plants for that matter
before it becomes limiting you simply do not possess a test kit that
even comes close.
Most researchers do not have the equipment to limit and test for Fe
limitation for FW algae. Some Marine specialist do.

Not quite my experience. A commercial low-iron test kit will read 0.1 ppm
nicely enough; and if I let the concentration get below that, my crypts
get ugly. But certainly there are lots of algae that will grow at that
concentration, so stopping algae by limiting iron isn't a useful idea.

A lot of people talk of _hair_ algae, specifically, being promoted by high
Fe concentration. I wonder if there's something to that. (But what does
it matter? If people are adding iron in order to grow plants, they surely
have algae-eating fish, and they'll never see hair algae. If they don't
have algae eaters, it's hopeless anyway.)


--
Dan Drake

http://www.dandrake.com